Processing apparatus for objects

ABSTRACT

Cylindrical cans each with one closed and one open end are metered one by one between a pair of differentially corotating driving wheels having resilient rims that grasp each can by the closed end and spin it against a rotating printing wheel so as to imprint a band of ink completely around the can; and the can is then discharged downwardly onto a ramp guide on which it rolls in the direction of spin, away from and out of the apparatus. The ramp guide includes levers activated by the can to inhibit metering of the cans into the apparatus if there is a stoppage and backing up of the can flow; and to meter a predetermined amount of ink to the printing wheel on passage of each can, so that just the right amount of ink is printed on, regardless of the rate of flow of the cans.

United States Patent Thomas D. Birchall;

Johnnie L. Powell, Turlock, Calif. 770,509

Oct. 25, 1968 Feb. 23, 1971 Mandrel Industries, Inc. Houston, Tex.

lnventors App]. No. Filed Patented Assignee References Cited UNITED STATES PATENTS Primary Examiner-John P. Mclntosh Attorney-Robert G. Clay ABSTRACT: Cylindrical cans each with one closed and one open end are metered one by one between a pair of differentially corotating driving wheelshaving resilient rims that grasp each can by the closed end and spin it against a rotating printing wheel so as to imprint a band of ink completely around the can; and the can is then discharged downwardly onto a ramp guide on which it rolls in the direction of spin, away from and out of the apparatus. The ramp guide includes levers activated by the can to inhibit metering of the cans into the apparatus if there is a stoppage and backing up of the can flow; and to meter a predetermined amount of ink to the printing wheel on passage of each can, so that just the right amount 1,691,297 l1/1928 Meller 118/233 ofink is printed on, regardless ofthe rate offlow ofthe cans.

r T C 53 i 13* 43 I 54 I3 1 I i I'L fI 1 i '1. 4e 3 L I I 15 l3 I 37 33 I 37 7 1,7 L 34 ?7 PAIENTEU {55231971 3.565034 sum -1 BF 3 INVENTORS MAS, D. BIRCHALL BY I NNIE L. POWELL ATTORNEY PATENTED FEB23 lsn INVENTORS THOMAS D. BIRCHALL JOHNNIE L. POWELL BY I flaw e4 ATTORNEY PATENIEU FEB23 15m SHEET 3 BF 3 INVENTORS THOMAS D. Bl RCHALL JOHNNIE L. POWELL ATTORNEY PROCESSING APPARATUS FOR OBJECTS FIELD OF THE INVENTION The present invention relates to processing means for objects, and particularly to apparatus for printing marks upon cans.

Previously in the art, printing wheels for open ended cans have been arranged to drive the cans as well as to make the printed marks thereon, and engage the cans remote from their closed ends, so that the cans are often deformed by the printing operation, and the mark is not well made. Also the metering of the cans into and out of the apparatus has not been well provided for; and the ink has usually been supplied to the printing wheel in a steady metered drip, so that variations in the rate of flow of cans cause either too little or too much ink to be imprinted.

Accordingly, it is an object of the present invention to provide a can marking apparatus that drives the cans in such a way as to avoid deforming the cans in passage.

It is another object of the invention to provide a can marking apparatus that meters the cans in accordance with their rate of flow.

It is further an object of the invention to provide a can marking apparatus that meters the ink to the cans in accordance with the rate of flow of the cans.

These and other objects are achieved in the present invention by means of an arrangement in which cylindrical cans each with one closed and one open end are metered one by onevbetween a pair of differentially corotating driving wheels having resilient rims that grasp each can by the closed end and spin it against a rotating printing wheel so as to imprint a band of ink completely around the can; and the can is then discharged downwardly onto a ramp guide on which it rolls in the direction of spin, away from and out of the apparatus. The ramp guide includes levers activated by the can to inhibit metering of the cans into the apparatus if there is a stoppage and backup of the can flow; and to meter a predetermined amount of ink to the printing wheel on passage of each can, so that just the right amount of ink is printed on, regardless of the rate of flow of the cans.

DESCRIPTION OF THE DRAWING FIG. I is a broken-away front elevational view of the apparatus of the invention;

FIG. 2 is an enlarged cross-sectional view taken along the plane of lines 2-2 of FIG. 1;

FIG. 3 is a further enlarged fragmentary view of a-portion of the apparatus shown in FIGS. I and 2;

FIG. 4 is an enlarged cross-sectional view taken along the plane of lines M of FIG. 1;

FIG. 5 is cross-sectional view taken along the plane of lines 5-5 of FIG. 1;

FIG. 6 is a back elevational view of the apparatus shown in FIG. I; and

FIG. 7 is a side elevational view taken along the plane of lines 7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and particularly to FIG. 1 thereof, there is shown a can marking device including a vertical base I], a face plate 12 mounted in parallel spaced relation thereto, and a pair of guide tracks 13 for guiding a series of cans I4 vertically down into the apparatus between the base 11 and face plate 12. A star wheel 15 is mounted at the entrance to stop the incoming cans and meter them one by one into the apparatus. Whenever the starwheel 15 rotates onefourth of a turn, one of the cans is metered into the machine and drops directly down between a pair of corotating (i.e., rotating in the same absolute direction) drive wheels 16 and I7, which quickly spin the can through at least one full revolution about its own axis, while another portion of the can is being marked by an inked printing wheel I8, and then drops the can onto a set of guides 21 and 22 for discharge from the machine. The guide 22 is movable downwardly in response to the weight of the can and when in the down position, through suitable linkages, causes blocking of ingress of other cans; but as the can leaves the machine between a pair of discharge guides 23 and 24, the lower guide 22 rises to permit the star wheel 15 to meter in another can. The guide 21 is also movable in response to the passage of the can, as the can is driven downwardly by the drive wheels l6, l7, and is used to operate an ink pumping apparatus 26, to be described in greater detail hereinafter.

Referring now to FIG. 2, one of the major advantages of the present invention is illustrated which is that the cans 14 which are open at the top 31 but have closed bottoms 32 and beaded bottom rims 33, are seized and driven by the drive wheels 16 and 17 by the structurally stiff and rigid beaded rim portion 33 thereof, so that the can is not distorted during the driving operation, nor does distortion or out-of-roundness of the can near the open end thereof have any direct effect on the driving operation. The drive wheels 16 and 17 both have chamfcred outer circumferential portions 34 and radially inward flat land portions 36, for solidly engaging the bottoms of the cans; and each wheel 16, 17 has a driving tire 37 mounted thereon and made of hard rubber or suitable plastic material for driving the beaded portion of the can. The inking wheel 18 is mounted on the same driving axle 41 as the driving wheel 17 and both are keyed for rotation with the axle, with the ink wheel I8 spaced for any desired distance axially from the driving wheel so as to cause an ink mark or band 42 to be imprinted on the can as it spins. By changing the axial position of the wheel 18, the mark 42 can be imprinted 'on any desired portion of the can; and two or more wheels 18 may be used to print a number of marks 42, either in the same or in different colors, simultaneously on the can. The wheel 18 is composed of a central web disc 43, on the flanged circumference of which is moulded a rubber printing tire 44 having a radially extending rubber printing flange 46 of just the right axial thickness to make the mark 42 of the width desired. The reason for having an overall thickness for the tire 44 that is greater than the axial thickness of the printing portion 46 is to provide the printing element with sufficient stiffness and support to prevent axial flopping or bending of the printing element when it is brought into pressurized engagement with the can. The rubber printing element 44 is also provided with a plurality of axially perforating slots 47, particularly as illustrated in FIG. 3, the slots lying in a chordal plane (Le, a plane defining a chord) of the printing wheel so as to provide the printing element with a suitable degree of radial flexibility to accommodate the wheel to irregularities of roundness of the can without losing the pressure necessary for printingor, on the other hand, applying too much pressure and deforming the can, and accordingly, the portion 46 has a slightly greater diameter than the drive wheel 17 at the point of tangency of the drive wheel and the can. Rubber tires embodying such slots are already known in the lapidary art.

To provide the necessary backup pressure for the printing operation, there is also mounted on the same shaft 48 as the drive wheel 16 a printing backup wheel 52 including a mounting wheel portion 53, two side plates 54, and a rubber backup pressure tire 56 which, although not shown, may have substantially the same construction as the tire 44 except that such a tire 56 would be only substantially of the same axial thickness as printing flange 46 of the tire 44, and would not have a separate flange such as the flange 46. This wheel 52 is mounted so that the tire 56 engages the can in such a manner that it is just barely axially offset from the mark 42 in either axial direction, and gives the best possible backup for the printing flange 46 without any danger of smearing the ink mark 42. It has been found in practice that even when-more than one printing wheel 13 is used, the single backup wheel 52 is sufficient; it is positioned between the plane of the open ends ofthe cans and the plane of the nearest printing wheel.

The manner in which the drive wheels I6, I7 are'm'ounted and rotated for the purpose of spinning the can through at least one full revolution while holding it in a suitable printing position, is illustrated in FIGS. 6 and 7. The base 11 consists of two spaced plates 61 and 62, which include between them in a guarding fashion a drive sprocket 63, and a pair of sprocket wheels 64 and 65; the sprocket 63 being driven by a motor 66 operating through a worm gear and slipping clutch device 67 of standard commercial manufacture. In this example, the sprocket wheel 64 has a greater number of teeth than the sprocket wheel 65, and as a result, the wheel 64 rotates more slowly than the wheel 65. Consequently, the driving wheel 17, which in H0. 1 rotates in a clockwise direction as shown by the arrow, rotates more slowly than the drive wheel 16 which in FIG. 1 rotates also in a clockwise direction and the can 14 is spun in a counterclockwise direction while being driven slowly through the printing position. The counterclockwise spinning direction of the can corresponds with the natural direction of roll that it will take up when it falls onto the guides 21, 22 and 24.

The precise number of teeth and the speed ratio between sprocket wheels 64, 65 may be varied according to the size of the can being processed and the operating speed desired. ln the illustrated embodiment sprocket wheel 64 has 24 teeth, and sprocket wheel 65 has teeth.

Returning to FIGS. 6 and 7, the metering operation is illustrated. Movable guide arm 22 is fixed on a shaft 71, which is mounted in a bearing to protrude through the two base plates 61 and 62, to the back side of the apparatus; and on the rearwardly extending end of the shaft 71 is fixedly mounted an arm 72 bearing a counterweight 73 of mass such that the arm 22 is normally urged upwardly so that an extending portion 74 thereof engages a stop 76; however, when the arm 22 receives the weight of a can 14, the arm pivots downwardly to come into engagement from above against the stop 76. This action causes the arm 72 to pivot through a range 77 and into the path of an arm 79, at the upper limit 78 of the range clockwise movement. The arm 79 is mounted for pivoting motion on a shaft 81, through a range 82, for restraining or permitting rotation of second star wheel 83, which is fixedly mounted on the same shaft 84 as the star wheel 15. The arm 79 has mounted thereon a ball bearing race 86, which is engaged by a cam 87, which in turn is fixedly mounted on the shaft 41 of sprocket wheel 64 and printing wheel 17, so that once on each revolution of printing wheel 17, the arm 79 is permitted to pivot in such a way that it releases the star wheel 83. The arm 79 is urged toward the releasing position by means ofa tension spring 88, and the natural timing of the release operation dictated by the cam 87 is such that one can 14 is metered into the apparatus on each revolution ofthe drive wheel. This timing is such that two cans are never admitted to the driving and printing wheels at the same time. The only time when the metering operation needs to be suspended is when the cans in the discharge portion 23, 24 of the apparatus are backed up to the degree that the last can is resting on the arm 22 and holding it in its downward position. At such a time, the arm 72, which has a flange 89, blocks the movement of arm 79 and prevents it from releasing the star wheels and admitting more cans. As a feature to prevent jamming of the star wheel apparatus, the arm 79 is provided with a subsidiary arm 91, which is mounted for pivoting motion as by means ofa pin 92 on the upper end ofthe arm 79. The arm 91 has a flange 93 which is the portion that actually engages the star wheel 83 and the lower portion of the arm 91 has a flange 94 which is urged into normally close engagement with the arm 79 as by means of a tension spring 96 stretched by the flange 94 and a pin 97 on the arm 79:

One of the important features of the invention is the ink pumping apparatus 26, which meters ink onto the printing wheel at a rate that is controlled by the rate of movement of the cans through the apparatus. It is quite normal in the canning plant to operate steadily for a time and then to have to stop the flow of cans for an indefinite period because oftraffic control problems farther down the line. Stoppages and movements of the cans are extremely irregular. One of the disadvantages of prior can marking devices was that ink was fed to the inking wheel at a steady rate, so that when the cans were stopped, the inking wheels got too much ink on them. Conversely, if the rate of ink application were adjusted to an average rate of can flow, then inevitably when the cans moved fast and steadily for a long period, the inking device would not get enough ink and the marks would be too faint. 1n the present invention, the inking wheels are given a charge of ink each time a can passes through the apparatus, and if no cans pass, the ink feeding is suspended. Referring to FIGS. 1 and 4, when a can 14 is driven down from between the drive wheels 16, 17 it first strikes the lever 21 which is mounted for free pivoting motion on the shaft 71, and is normally held in a counterclockwise position as illustrated in the FIG. 1. When a can is driven over the lever 21, the lever moves slightly clockwise as indicated by the arrow, and acting through a bell crank 10] and link member 102, it causes a pressure element 103 to temporarily pinch a rubber or plastic tube 104 that is provided as a part of the ink feeding line. The ink feeding line 106 extends from an ink holding receptacle 107 to a check valve 108, which permits upward but not downward flow of ink. Above the compressible tube 104 is a second check valve 109 which also permits upward but not downward flow of ink. The lever 102 slides longitudinally on a supporting pin 110 extended between the plates 12 and 72, and between a pair of tubular spacing elements 111, which latter also form an anvil against which the tube 104 is pinched by element 103. Thus, whenever the tube 104 is pinched, the ink in the tube is squeezed out through the upper check valve 109 toward the ink wheels, and when the pinching pressure is released by passage of can 14 from lever 21 to arm 22, the ink is sucked through check valve 108 into the tube 104 from the reservoir in the container 107. A metered amount of ink is thus sent to the apparatus by the passage of each can separately therethrough. The pinching element 103 is mounted on the end of a threaded shaft 112, which is threaded through flange 113 on the end of line 102, and is secured by a knurled lock nut 114, so that the precise pinching stroke and the amount of ink that is metered are accurately adjustable during the actual operation. lt will be clear that other pumping means could also be used. The metered ink passes upwardly through a tube 116 to a spigot 117 which spreads the ink upon a felt intermediate inking wheel 118, that is also engaged by inking rim 46 of inking wheel 18. The intermittent ink wheel 118 is of standard design and comprises a felt disc slightly wider than the rim 46, mounted between a pair of circular side plates 119, the entire wheel being mounted by free rotation at the end of an arm 121, which is in turn pivoted on a shaft 122 and urged by a tension spring 123 into pressurized engagement with the rim 46 of inking wheel 118. An alternate method for applying the ink would be to pump it into the center of the felt wheel 118. Of course, it will be understood that for each inking wheel 18 that is used, a separate intermediate wheel 118, spiggot 117, pumping tube 104, and reservoir container 107 must be employed, although only one link member 102 need be employed; in such case the flange 113 of the link 102 may be extended so as to provide mounting for a plurality of pressure members 103, 112, one for each of the pumping tubes 104.

Since in some operations it is desirable to be able to change the color of the printed mark very rapidly in the middle of a run of cans, and since at such times it is necessary to exchange the intermediate ink wheel 118 together with the associated pumping lines and ink reservoir 107, it is desirable to be able to seal the ink line of the detached apparatus against atmospheric air so as to prevent drying up of the ink in the lines and sticking of the check valves. For this purpose there is provided at the top of each ink line 116 a coupling 124 and a clamp 125 that may be tightened to produce the sealing effect that is desired.

We claim:

1. A processing apparatus for cans each having at least one closed end presenting an exterior beaded rim at said closed end, comprising:

an inked printing wheel for printing a circumferential marking band upon each can; I

a pair of spaced-apart differential-speed corotating driving wheels mounted in the same plane and in axial parallelism with said printing wheel axes but axially displaced from the printing wheel so as to engage opposite sides of each can and rotate each can for at least one fullrotation in contact with said printing wheel while driving said can past said printing wheel;

feeding means including a plurality of guide members arranged to guide said cans to and between said driving wheels with said beaded rim portion in the plane thereof, so that said cans are not substantially deformed when engaged by said driving wheels; and

said driving wheels being each provided with a resilient frictional rim portion so as to grippingly engage and drive only said beaded rim portion of each can therebetween.

2. A processing apparatus as recited in claim 1, wherein:

each of said driving wheels is also provided with a beveled flange portion extending radially beyond said resilient rim portion thereof and axially adjacent thereto so as to receive and guide a closed end of each can with said beaded rim portion thereof in the plane of said driving wheels.

3. A processing apparatus as recited in claim 2, wherein there is also provided: at least one resilient-rimmed backup wheel mounted for rotation in axial parallelism with and generally opposite said printing wheel so as to press each can firmly against said printing wheel in passage through said processing station.

4. A processing apparatus as recited in claim 3, wherein:

more than one printing wheel'is employed, but only one backup wheel; and

said backup wheel is axially positioned between the printing wheels and the end of the can thatis remote from said driving wheels.

5. A processing apparatus as recited inclaim 3,- wherein: at least said p rinting'wheel is provided with a resilient printing rim portion having elongated axial slots formed therein, each slot lying in a chordal plane of said printing wheel.

6. A processing apparatus as recited in claim 5, wherein: said backup wheel is also provided with a resilient rim portion having elongated axial slots formed therein, each slot lying in a chordal plane of said backup wheel. 1

7. A processing apparatus as recited in claim SQwherein:

said resilient printing'rim portion of fsaid printing wheel is formed with a body portion and a circumferential printing flange of predetermined axial thickness corresponding with the width of printing mark desired, said body portion containing said slots and being of substantiallygreater axial thickness than said printing flange so as to inhibit axial deflection of said printing rim under pressure.

8. A processing apparatus as recited in claim 3, wherein: a pair of drive shafts are provided, one being affixed to each of said drive wheels; said printing wheel being mounted on and affixed to one of said drive shafts; and said backup wheel being mounted on the other of said drive shafts. 1 9. A processing apparatus as recited in claim 1, wherein said objects are right-circular-cylindrical-cans, and wherein:

said apparatus is arranged with the axes of said drive wheels in the same horizontal plane and with feeding means disposed to feed said cans to said drive wheels from above, while said receiving means is disposed below said drive wheels to receive said cans as they pass downwardly between and from said drive wheel; said receiving means includes ramp guide means for conducting said cans in axially rolling motion downwardly and laterally beneath one of said drive wheels and out of said apparatus; and 1 Y v the lateral direction of said ramp guide means being selected so that the natural direction of roll of said cans thereon is the same as the direction of spin that is imparted to said cans by said differentially rotating drive wheels. 7

10. A processing apparatus as recited in claim 9, wherein: said feeding means is provided with metering means coupled to said printing wheel drive shaft for metering one can to said drive wheels upon each revolution of said printing wheel.

11. A processing apparatus as recited in claim 10, wherein:

said ramp guide means includes a pivoting guide member counterweighted toward an upper position and responsive to the weight of a can thereon to pivot toward a lower position;

said pivoting guide member being coupled to said metering means to inhibit the operation of said metering means when said pivoting guide member is in said lower position thereof; and

whereby upon a stoppage and accumulation of cans moving out of said apparatus, at least one of said cans eventually comes to rest on said pivoting guide member and stops the flow of cans into said apparatus from said feeding means.

12. A processing apparatus as recited in claim 1, wherein said objects are right-circular-cylindrical cans, and wherein said apparatus also includes:

ink supply means for said inked printing wheel;

means responsive to the passage of each can through said apparatus to meter a predetermined amount of ink from said ink supply means to said printing wheel; and

whereby the mark is printed on each can with just the right amount of ink, regardless of the rate of flow of said cans.

13. A processing apparatus as recited in claim 12, wherein:

said ink metering means includes a pivoting lever mounted for engagement by each can as said can is driven between and from said drive wheels; and

said ink supply means includes an ink reservoir and a pump means coupled to said lever for pumping actuation thereby to pump said predetermined amount of ink to said printing wheel upon the passage of each can.

14. A processing apparatus as recited in claim 13, wherein said pump means includes:

a conduit extending in an upstream to downstream direction from near the bottom of saidink reservoir and toward said printing wheel, a section of said conduit being formed of compressible'resilient tubing;

an anvil member positioned adjacent said resilient section of said conduit;

check valve means positioned in said conduit at both the upstream and downstream ends of said resilient section for permitting flow of ink only in said upstream to downstream direction toward said printing wheel;

a pinching element coupled to said lever for pinching said resilient section against said anvil element upon each actuation of said lever so as to squeeze the ink therein in said upstream to downstream direction through the downstream check valve means; and

the release of said lever upon passage of a can permitting expansion of said resilient section of said conduit to draw more ink from said reservoir, through the upstream check valve means, and into said resilient section.

15. A processing apparatus as recited in claim 14, and also including: a felt ink wheel positioned in tangential engagement with said printing wheel and at the downstream end of said conduit, for receiving ink therefrom and smoothly applying it to said printing wheel.

16. A processing apparatus as recited in claim 14, wherein:

a coupling is provided in said conduit downstream from said downstream check valve, for uncoupling and removing said reservoir and a portion of said conduit from said apparatus; and

said conduit also being provided with a closure clamp adjacent to and upstream from said coupling for preventing the drying of said ink when said coupling is uncoupled. 

1. A processing apparatus for cans each having at least one closed end presenting an exterior beaded rim at said closed end, comprising: an inked printing wheel for printing a circumferential marking band upon each can; a pair of spaced-apart differential-speed corotating driving wheels mounted in the same plane and in axial parallelism with said printing wheel axes but axially displaced from the printing wheel so as to engage opposite sides of each can and rotate each can for at least one full rotation in contact with said printing wheel while driving said can past said printing wheel; feeding means including a plurality of guide members arranged to guide said cans to and between said driving wheels with said beaded rim portion in the plane thereof, so that said cans are not substantially deformed when engaged by said driving wheels; and said driving wheels being each provided with a resilient frictional rim portion so as to grippingly engage and drive only said beaded rim portion of each can therebetween.
 2. A processing apparatus as recited in claim 1, wherein: each of said driving wheels is also provided with a beveled flange portion extending radially beyond said resilient rim portion thereof and axially adjacent thereto so as to receive and guide a closed end of each can with said beaded rim portion thereof in the plane of said driving wheels.
 3. A processing apparatus as recited in claim 2, wherein there is also provided: at least one resilient-rimmed backup wheel mounted for rotation in axial parallelism with and generally opposite said printing wheel so as to press each can firmly against said printing wheel in passage through said processing station.
 4. A processing apparatus as recited in claim 3, wherein: more than one printing wheel is employed, but only one backup wheel; and said backup wheel is axially positioned between the printing wheels and the end of the can that is remote from said driving wheels.
 5. A processing apparatus as recited in claim 3, wherein: at least said pRinting wheel is provided with a resilient printing rim portion having elongated axial slots formed therein, each slot lying in a chordal plane of said printing wheel.
 6. A processing apparatus as recited in claim 5, wherein: said backup wheel is also provided with a resilient rim portion having elongated axial slots formed therein, each slot lying in a chordal plane of said backup wheel.
 7. A processing apparatus as recited in claim 5, wherein: said resilient printing rim portion of said printing wheel is formed with a body portion and a circumferential printing flange of predetermined axial thickness corresponding with the width of printing mark desired, said body portion containing said slots and being of substantially greater axial thickness than said printing flange so as to inhibit axial deflection of said printing rim under pressure.
 8. A processing apparatus as recited in claim 3, wherein: a pair of drive shafts are provided, one being affixed to each of said drive wheels; said printing wheel being mounted on and affixed to one of said drive shafts; and said backup wheel being mounted on the other of said drive shafts.
 9. A processing apparatus as recited in claim 1, wherein said objects are right-circular-cylindrical cans, and wherein: said apparatus is arranged with the axes of said drive wheels in the same horizontal plane and with feeding means disposed to feed said cans to said drive wheels from above, while said receiving means is disposed below said drive wheels to receive said cans as they pass downwardly between and from said drive wheel; said receiving means includes ramp guide means for conducting said cans in axially rolling motion downwardly and laterally beneath one of said drive wheels and out of said apparatus; and the lateral direction of said ramp guide means being selected so that the natural direction of roll of said cans thereon is the same as the direction of spin that is imparted to said cans by said differentially rotating drive wheels.
 10. A processing apparatus as recited in claim 9, wherein: said feeding means is provided with metering means coupled to said printing wheel drive shaft for metering one can to said drive wheels upon each revolution of said printing wheel.
 11. A processing apparatus as recited in claim 10, wherein: said ramp guide means includes a pivoting guide member counterweighted toward an upper position and responsive to the weight of a can thereon to pivot toward a lower position; said pivoting guide member being coupled to said metering means to inhibit the operation of said metering means when said pivoting guide member is in said lower position thereof; and whereby upon a stoppage and accumulation of cans moving out of said apparatus, at least one of said cans eventually comes to rest on said pivoting guide member and stops the flow of cans into said apparatus from said feeding means.
 12. A processing apparatus as recited in claim 1, wherein said objects are right-circular-cylindrical cans, and wherein said apparatus also includes: ink supply means for said inked printing wheel; means responsive to the passage of each can through said apparatus to meter a predetermined amount of ink from said ink supply means to said printing wheel; and whereby the mark is printed on each can with just the right amount of ink, regardless of the rate of flow of said cans.
 13. A processing apparatus as recited in claim 12, wherein: said ink metering means includes a pivoting lever mounted for engagement by each can as said can is driven between and from said drive wheels; and said ink supply means includes an ink reservoir and a pump means coupled to said lever for pumping actuation thereby to pump said predetermined amount of ink to said printing wheel upon the passage of each can.
 14. A processing apparatus as recited in claim 13, wherein said pump means includes: a conduit extending in an upstream to downstream dIrection from near the bottom of said ink reservoir and toward said printing wheel, a section of said conduit being formed of compressible resilient tubing; an anvil member positioned adjacent said resilient section of said conduit; check valve means positioned in said conduit at both the upstream and downstream ends of said resilient section for permitting flow of ink only in said upstream to downstream direction toward said printing wheel; a pinching element coupled to said lever for pinching said resilient section against said anvil element upon each actuation of said lever so as to squeeze the ink therein in said upstream to downstream direction through the downstream check valve means; and the release of said lever upon passage of a can permitting expansion of said resilient section of said conduit to draw more ink from said reservoir, through the upstream check valve means, and into said resilient section.
 15. A processing apparatus as recited in claim 14, and also including: a felt ink wheel positioned in tangential engagement with said printing wheel and at the downstream end of said conduit, for receiving ink therefrom and smoothly applying it to said printing wheel.
 16. A processing apparatus as recited in claim 14, wherein: a coupling is provided in said conduit downstream from said downstream check valve, for uncoupling and removing said reservoir and a portion of said conduit from said apparatus; and said conduit also being provided with a closure clamp adjacent to and upstream from said coupling for preventing the drying of said ink when said coupling is uncoupled. 